/Engine/Source/Editor/UnrealEd/Classes/Editor/EditorEngine.h
Creates a SPIEViewport for the specified instance. This is used for Play in New Window, but not for instances that live in the level editor viewport.
[TSharedRef](API\Runtime\Core\Templates\TSharedRef)< class SPIEViewport > GeneratePIEViewportWindow ( const [FRequestPlaySessionParams](API\Editor\UnrealEd\FRequestPlaySessionParams) & InSessionParams, int32 InViewportIndex, const [FWorldContext](API\Runtime\Engine\Engine\FWorldContext) & InWorldContext, EPlayNetMode InNetMode, [UGameViewportClient](API\Runtime\Engine\Engine\UGameViewportClient) * InViewportClient, [FSlatePlayInEditorInfo](API\Editor\UnrealEd\FSlatePlayInEditorInfo) & InSlateInfo )